Magnetic tape recording apparatus and method, magnetic tape playback apparatus and method, format for magnetic tape, and storage medium product

ABSTRACT

Pictures in number indicated by a value (3 in one example) of M in a GOP structure are set as one unit. AUX data (denoted by U in FIG.  32 ) related to those pictures, audio data (denoted by A in FIG.  32 ) corresponding to those pictures, and AUX data (denoted by X in FIG.  32 ) related to the audio data are arranged together at the head of 16 tracks that undergo interleaving. Subsequent to those data, one unit of pictures (3 pictures in one example) is arranged. An HD video signal and an HD audio signal can be recorded and played back with certainty.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnetic tape recording apparatus andmethod, a magnetic tape playback apparatus and method, a format for amagnetic tape, and a storage medium product. More particularly, thepresent invention relates to a magnetic tape recording apparatus andmethod, a magnetic tape playback apparatus and method, a format for amagnetic tape, and a storage medium product, which enablehigh-definition video data to be recorded on or played back from themagnetic tape.

2. Description of the Related Art

Recently, with the progress of compression technology, video data, etc.have also been compressed by the DV (Digital Video) technique, forexample, and recorded on a magnetic tape. A format for such compressionof video data, etc. is specified as a DV format for consumer-orienteddigital video cassette recorders.

FIG. 1 illustrates a construction of one track in a conventional DVformat. In the DV format, video data is recorded after being subjectedto the 24–25 conversion. The number of bits denoted by each numeral inFIG. 1 represents a value after being subjected to the 24–25 conversion.

A region corresponding to a contact angle of 174 degrees of a magnetictape around a rotary magnetic head provides an effective region of onetrack. Outside the region of one track, an overwrite margin with alength of 1250 bits is formed. The overwrite margin serves to preventdata from remaining after being erased.

When the rotary head is rotated in sync with frequency of 60×1000/1001Hz, the region of one track has a length of 134975 bits, and when therotary head is rotated in sync with frequency of 60 Hz, it has a lengthof 134850 bits.

An ITI (Insert and Track Information) sector, an audio sector, a videosector, and a subcode sector are arranged in one track successively inthe trace direction of the rotary head (i.e., in the direction from lefttoward right in FIG. 1). A gap G1 is formed between the ITI sector andthe audio sector, a gap G2 is formed between the audio sector and thevideo sector, and a gap G3 is formed between the video sector and thesubcode sector.

The ITI sector has a length of 3600 bits, and a preamble of 1400 bits isarranged at the head of the ITI sector to produce a clock. Subsequent tothe ITI sector, an SSA (Start Sync Area) and a TIA (Track InformationArea) are arranged in length of 1920 bits in this order. A bit train(sync number) necessary for detecting the position of the TIA isarranged in the SSA. Information indicating that video data is in the DVformat for consumer-oriented equipment, information indicating whetherthe mode is an SP or LP mode, information indicating a pattern of apilot signal of one frame, etc. are recorded in the TIA. Subsequent tothe TIA, a postamble of 280 bits is arranged.

The gap G1 has a length of 625 bits.

The audio sector has a length of 11550 bits. At the head and end of theaudio sector, 400 bits and 500 bits are used for a preamble and apostamble, respectively, and 10650 bits between the preamble and thepostamble are used for data (audio data).

The gap G2 has a length of 700 bits.

The video sector has a length of 113225 bits. At the head and end of thevideo sector, 400 bits and 925 bits are used for a preamble and apostamble, respectively, and 111900 bits between the preamble and thepostamble are used for data (video data).

The gap G3 has a length of 1550 bits.

The subcode sector has a length of 3725 bits when the rotary head isrotated at frequency of 60×1000/1001 Hz, and has a length of 3600 bitswhen the rotary head is rotated at frequency of 60 Hz. At the head andend of the subcode sector, 1200 bits are used for a preamble and 1325bits (when the rotary head is rotated at frequency of 60×1000/1001 Hz)or 1200 bits (when the rotary head is rotated at frequency of 60 Hz) areused for a postamble, respectively, and 1200 bits between the preambleand the postamble are used for data (subcode).

In the conventional DV format, as described above, not only the gaps G1to G3 are formed between adjacent two of the ITI sector, audio sector,video sector and the subcode sector, but also the preamble and thepostamble are provided for each sector. Therefore, the conventional DVformat has a drawback that it includes a relatively large amount ofso-called overhead and hence cannot provide a sufficiently high level ofrecording rate for effective data.

Such a drawback leads to a problem as follows. When recordinghigh-definition video data (hereinafter referred to as HD video data),for example, a bit rate of about 25 Mbps is required. However, a bitrate obtained in the conventional DV format by MP@HL in accordance withMPEG (Moving Picture Expert Group) is about 22 Mbps at maximum exceptfor search video data. As a result, although the conventional DV formatcan record standard-definition video data (hereinafter referred to as SDvideo data), but it cannot ensure a satisfactory level of image qualitywhen the HD video data is compressed and recorded by MP@HL or MP@H-14.

SUMMARY OF THE INVENTION

In view of the state of the art set forth above, it is an object of thepresent invention to enable HD video data to be recorded on and playedback from a magnetic tape.

A magnetic tape recording apparatus according to the present inventioncomprises a first acquiring unit for acquiring video data, audio data orsearch data; a second acquiring unit for acquiring auxiliary data havinga variable length and related to the data acquired by the firstacquiring unit; a selecting unit for selecting, as first group data, oneof the data acquired by the first acquiring unit and the data acquiredby the second acquiring unit; a third acquiring unit for acquiringsecond group data containing a subcode related to the first group data;a merging unit for merging the first group data and the second groupdata such that the first group data and the second group data arecontinuously arranged on tracks of a magnetic tape without being spacedaway from each other; and a supplying unit for supplying data merged bythe merging unit to a rotary head to record the merged data on themagnetic tape.

The first acquiring unit may acquire, as the first group data, the videodata in edit units.

Preferably, the second acquiring unit acquires, as the second groupdata, auxiliary data related to the audio data and auxiliary datarelated to the video data; and the merging unit merges the auxiliarydata related to the audio data, the audio data, the auxiliary datarelated to the video data, and the video data to be arranged in thisorder.

The second acquiring unit may further acquire auxiliary data requiredfor pre-playback; and the merging unit may merge the auxiliary datarequired for pre-playback to be arranged at the head of an edit unit ofthe video data.

Preferably, the auxiliary data required for pre-playback includes thecontents recorded in a subcode sector.

A magnetic tape recording method according to the present inventioncomprises a first acquiring step of acquiring video data, audio data orsearch data; a second acquiring step of acquiring auxiliary data havinga variable length and related to the data acquired by processing in thefirst acquiring step; a selecting step of selecting, as first groupdata, one of the data acquired by processing in the first acquiring stepand the data acquired by processing in the second acquiring step; athird acquiring step of acquiring second group data containing a subcoderelated to the first group data; a merging step of merging the firstgroup data and the second group data such that the first group data andthe second group data are continuously arranged on tracks of a magnetictape without being spaced away from each other; and a supplying step ofsupplying data merged by processing in the merging step to a rotary headto record the merged data on the magnetic tape.

A storage medium product according to the present invention stores acomputer-readable program comprising a first acquiring step of acquiringvideo data, audio data or search data; a second acquiring step ofacquiring auxiliary data having a variable length and related to thedata acquired by processing in the first acquiring step; a selectingstep of selecting, as first group data, one of the data acquired byprocessing in the first acquiring step and the data acquired byprocessing in the second acquiring step; a third acquiring step ofacquiring second group data containing a subcode related to the firstgroup data; a merging step of merging the first group data and thesecond group data such that the first group data and the second groupdata are continuously arranged on tracks of a magnetic tape withoutbeing spaced away from each other; and a supplying step of supplyingdata merged by processing in the merging step to a rotary head to recordthe merged data on the magnetic tape.

In a format for a magnetic tape according to the present invention,first group data comprising video data, audio data or search data, orcomprising auxiliary data having a variable length and related to thevideo data, the audio data or the search data, and second group datacontaining a subcode related to the video data, the audio data or thesearch data are recorded such that the first group data and the secondgroup data are continuously arranged on tracks of the magnetic tapewithout being spaced away from each other.

With the magnetic tape recording apparatus, the magnetic tape recordingmethod, and the storage medium product storing the computer-readableprogram according to the present invention, video data, audio data orsearch data is acquired, and auxiliary data having a variable length andrelated to the acquired data is acquired. One of these two types ofacquired data is selected as first group data, and second group datacontaining a subcode related to the first group data is acquired. Thefirst group data and the second group data are merged such that thefirst group data and the second group data are continuously arranged ontracks of a magnetic tape without being spaced away from each other.Merged data is recorded on the magnetic tape.

A magnetic tape playback apparatus according to the present inventioncomprises an acquiring unit for acquiring auxiliary data, as first groupdata, having a variable length and related to compressed high-definitionor standard-definition video data, audio data or search data, or secondgroup data containing a subcode related to the first group data; and adecompressing unit for decompressing the compressed high-definitionvideo data, which is contained in data reproduced from a magnetic tapewith a rotary head, by using the auxiliary data or the second group dataacquired by the acquiring unit.

A magnetic tape playback method according to the present inventioncomprises an acquiring step of acquiring auxiliary data, as first groupdata, having a variable length and related to compressed high-definitionor standard-definition video data, audio data or search data, or secondgroup data containing a subcode related to the first group data; and adecompressing step of decompressing the compressed high-definition videodata, which is contained in the data reproduced from a magnetic tapewith a rotary head, by using the auxiliary data or the second group dataacquired by processing in the acquiring step.

A storage medium product according to the present invention stores acomputer-readable program comprising an acquiring step of acquiringauxiliary data, as first group data, having a variable length andrelated to compressed high-definition or standard-definition video data,audio data or search data, or second group data containing a subcoderelated to the first group data; and a decompressing step ofdecompressing the compressed high-definition video data, which iscontained in data reproduced from a magnetic tape with a rotary head, byusing the auxiliary data or the second group data acquired by processingin the acquiring step.

With the magnetic tape playback apparatus, the magnetic tape playbackmethod, and the storage medium product storing the computer-readableprogram according to the present invention, auxiliary data, as firstgroup data, having a variable length and related to compressedhigh-definition or standard-definition video data, audio data or searchdata, or second group data containing a subcode related to the firstgroup data is acquired. The compressed high-definition video data, whichis contained in data reproduced from a magnetic tape with a rotary head,is decompressed by using the acquired auxiliary data or second groupdata.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representation for explaining an arrangement of tracksectors in a conventional DV format;

FIG. 2 is a block diagram showing one example of construction of arecording system of a magnetic tape recording/playback apparatusaccording to the present invention;

FIG. 3 is a representation for explaining a format of tracks formed on amagnetic tape shown in FIG. 2;

FIG. 4 is a chart for explaining a pilot signal for tracking controlrecorded in one track shown in FIG. 3;

FIG. 5 is a chart for explaining another pilot signal for trackingcontrol recorded in another track shown in FIG. 3;

FIG. 6 is a chart for explaining still another pilot signal recorded instill another track shown in FIG. 3;

FIG. 7 is a representation for explaining a sector arrangement withineach track shown in FIG. 3;

FIG. 8 is a representation for explaining patterns of a preamble and apostamble shown in FIG. 7;

FIG. 9 is a representation for explaining a structure of a main sectorshown in FIG. 7;

FIGS. 10A and 10B are representations for explaining a main sector IDshown in FIG. 9;

FIG. 11 is a representation for explaining an SB header of the mainsector shown in FIG. 9;

FIG. 12 shows data representing a search data;

FIG. 13 shows data representing types of AUX data;

FIG. 14 is a table for explaining system data having a fixed length;

FIG. 15 is a table for explaining system data having a variable length;

FIGS. 16A, 16B, 16C and 16D are representations for explaining formatsof system data having a fixed length;

FIGS. 17A, 17B, 17C and 17D are representations for explaining formatsof system data having a variable length;

FIGS. 18A and 18B are tables for explaining information defined in aheader section;

FIG. 19 is another representation for explaining the format of thesystem data having a fixed length;

FIG. 20 is another representation for explaining the format of thesystem data having a variable length;

FIG. 21 is a representation for explaining average values of datarecorded in the main sector;

FIG. 22 is a representation for explaining a structure of a subcodesector shown in FIG. 7;

FIG. 23 is a table for explaining a subcode sync block ID;

FIGS. 24A and 24B are representations for explaining subcode data;

FIG. 25 is another representation for explaining the conventional DVformat;

FIG. 26 is a table for explaining tape position information;

FIG. 27 is a representation for explaining an EPO;

FIG. 28 is a table for explaining an ECCTB;

FIG. 29 shows data for an audio mode;

FIG. 30 shows data for a video mode;

FIG. 31 is a table for explaining DATA-H;

FIG. 32 is a representation for explaining data in a recorded state;

FIG. 33 is a representation for explaining a process for detecting amain sector corresponding to a subcode sector;

FIG. 34 is a table for explaining the AUX data;

FIG. 35 is another representation for explaining a process for detectinga main sector corresponding to a subcode sector; and

FIG. 36 is a block diagram showing one example of construction of aplayback system of the magnetic tape recording/playback apparatusaccording to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 2 shows one example of construction of a recording system of amagnetic tape recording/playback apparatus to which the presentinvention is applied. A video data compressing unit 1 compresses aninputted HD video signal by, e.g., MP@HL or MP@H-14 in accordance withMPEG.

An audio data compressing unit 2 compresses an audio signal, whichcorresponds to the HD video signal, by an audio compression method inaccordance with MPEG1 layer2 or AAC, for example. The audio signal iscompressed to a rate of 256 Kbps to 384 Kbps by the audio datacompressing unit 2.

System data made up of AUX (auxiliary) data, subcode data, etc. isinputted to a terminal 3 from a controller 13. The system data containsdata representing text information externally inputted as additionaldata, associated with the video and audio signals, to indicate thecopyright, shooting situation, etc., a title time code (TTC) forassisting a search, editing, etc., track position information, apparatussetting information, and so on.

A switch 4 is changed over by the controller 13 to select an output ofthe video data compressing unit 1, an output of the audio datacompressing unit 2, or the system data supplied through the terminal 3at the predetermined timing for supply to an error code and ID addingunit 5.

The error code and ID adding unit 5 adds an error detecting/correctingcode and an ID to the data inputted through the switch 4, and carriesout an interleaving process among 16 tracks. Resulting data is outputtedto a 24–25 converter 6.

The 24–25 converter 6 adds redundant one bit, which is selected toenhance components of a pilot signal for tracking so as to appear at ahigher level, for converting the inputted data in units of 24 bits intodata in units of 25 bits.

A sync generator 7 generates sync data and amble data that are added tomain data (FIG. 9) and subcode data (FIG. 22) described later.

A switch 8 is controlled by the controller 13 to select one of an outputof the 24–25 converter 6 and an output of the sync generator 7 foroutputting to a modulator 9.

The modulator 9 modulates the data inputted through the switch 8 by amethod (which is the same as that used for the conventional DV format)suitable for recording on a magnetic tape 21, and supplies modulateddata to a parallel/serial (P/S) converter 10.

The parallel/serial converter 10 converts the inputted parallel datainto serial data.

An amplifier 11 amplifies the data inputted from the parallel/serialconverter 10 and supplies amplified data to a rotary head 12, which isattached to and rotated by a rotary drum (not shown), for recording ofthe data on the magnetic tape 21.

FIG. 3 represents a format of tracks formed on the magnetic tape 21 bythe rotary head 12. The rotary head 12 traces the magnetic tape 21 inthe direction from lower right toward upper left as viewed in thedrawing, whereby tracks inclined relative to the lengthwise direction ofthe magnetic tape 21 are formed. The magnetic tape 21 travels in thedirection from right toward left as viewed in the drawing.

Each track is formed as one of F0, F1 and F2 depending on the type ofpilot signal for tracking control, which is recorded in the track. Thetracks are formed in the order of F0, F1, F0, F2, F0, F1, F0 and F2.

The track F0 records therein, as shown in FIG. 4, no pilot signals offrequency f1 and f2. The track F1 records therein, as shown in FIG. 5,the pilot signal of frequency f1. The track F2 records therein, as shownin FIG. 6, the pilot signal of frequency f2.

The frequencies f1, f2 are set respectively to values that are 1/90 and1/60 of the recording frequency of channel bits.

As shown in FIG. 4, the depth of notches at the frequencies f1, f2 inthe track F0 is set to 9 dB. On the other hand, as shown in FIG. 5 orFIG. 6, the CNR (Carrier to Noise Ratio) of the pilot signal offrequency f1 or f2 is set to a value larger than 16 dB but smaller than19 dB. Further, the depth of notches at the frequencies f1, f2 in thetrack F1 or F2 is set to a value larger than 3 dB.

A track pattern having such frequency characteristics is similar to thatin the case of using the conventional DV format. A recording rate isabout 40 Mbps, i.e., 300 tracks per second. Accordingly, a magnetictape, a rotary head, a driving system, a demodulation system, and acontrol system of a consumer-oriented digital video cassette recordercan be used, as they are, in this embodiment.

Track pair numbers are set to tracks. Each track pair number is assignedfor each track pair, i.e., two tracks which are scanned at a time by twoheads having a positive azimuth and a negative azimuth. Track pairnumbers from 0 to 31 are assigned in an example of FIG. 3. The trackpair number 0, 8, 16 or 24 is set to the track pair at the head of every16 tracks which undergoes interleaving (although the track pairs to beassigned with the numbers 16 and 24 are not shown).

FIG. 7 shows one example of a sector format (sector arrangement) withineach track. In FIG. 7, the number of bits indicating the length of eachsector or section is represented by the length after being subjected tothe 24–25 conversion. One track has a length of 134975 bits when therotary head 12 is rotated at frequency of 60×1000/1001 Hz, and has alength of 134850 bits when it is rotated at frequency of 60 Hz. Thelength of one track corresponds to a contact angle of 174 degrees of themagnetic tape 21 around the rotary head 12. Subsequent to one track, anoverwrite margin of 1250 bits is formed. The overwrite margin serves toprevent data from remaining after being erased.

In FIG. 7, the rotary head 12 traces the track in the direction fromleft toward right. A preamble of 1800 bits is arranged at the head ofthe track. Data in combination of a pattern A and a pattern B shown inFIG. 8, by way of example, which are required to produce a clock, isrecorded in the preamble. In the pattern A and the pattern B, values 0and 1 are reversed between them. By properly combining those patterns, atracking pattern for each of the tracks F0, F1 and F2, shown in FIGS. 4to 6, can be obtained. Note that run patterns in FIG. 8 representpatterns resulted after the 24–25 conversion executed by the 24–25converter 6 in FIG. 2.

Subsequent to the preamble of 1800 bits, a main sector with a length of130425 bits is arranged. FIG. 9 shows a structure of the main sector.The main sector is subjected to normal playback and search playback.

As shown in FIG. 9, the main sector is made up of 141 sync blocks eachhaving a length of 888 bits (111 bytes).

Of 141 sync blocks, 123 sync blocks each comprise a 16-bit sync, 24-bitID, 8-bit sync block (SB) header, 760-bit main data, and an 80-bitparity C1.

The sync is generated by the sync generator 7.

The ID is made up of, as shown in FIG. 10A, three IDs, i.e., ID0 to ID2,each having a length of 1 byte.

Of b7-b0 of ID0, b7-b5 define the format type of the track, and b4-b0define the track pair number.

In addition to the type shown in FIG. 7, the track format may be of, forexample, the type wherein another ITI sector is further provided and themain sector is made up of 139 sync blocks, or the type wherein anotherITI sector and an after-recording sector comprising 7 sync blocks arefurther provided and the main sector is made up of 129 sync blocks.Stated otherwise, an ID or the like for identifying the type of usableformat is allocated to b7-b5 of ID0. By thus arranging the ID toidentify the type of track format, it is possible to execute ademodulation process adapted for the type of each format, and toreproduce data in an appropriate manner.

The sync block number is allocated to ID1.

Information indicating whether the data recorded in the main sector isnewly recorded one (i.e., data recorded for the first time in a vacantstate) or overwritten one (i.e., data recorded on previously recordeddata) is allocated to ID2 as one byte of overwrite protect. In the caseof overwriting, for example, if underlying data remains due to, e.g.,instantaneous clogging of the head, newly recorded data is corrected(erroneously corrected) based on the parity C1. To prevent sucherroneous correction, the newly recorded data and the overwritten dataare distinguished with the byte of overwrite protect. If the underlyingdata is determined as being remained, it is possible to make all of therelevant sync blocks invalid (handle them as a burst error) and carryout erasure correction based on a parity C2.

Fig. 10B shows ID0 to ID2 contained in each of the 141 sync blocks. ID0to ID2 are added by the error code and ID adding unit 5.

As shown in FIG. 11, the SB header comprises 8 bits of b7-b0. Of b7-b0,b7-b5 set a predetermined value indicating the type of main data (suchas audio data, video data, search video data, transport stream data, andAUX data), and b4-b0 set a predetermined value indicating details of themain data.

A value 0 of b7-b5 indicates that the main data is video data (PES videodata) in a PES (Program Elementary Stream) format in accordance withMPEG2. A value 1 of b7-b5 indicates that the main data is audio data(PES audio data) in the PES format. In this case, data indicatingwhether the data (video or audio data) is partial (less than 95 bytes)or full (95 bytes) is allocated to b4 of b4-b0, and data indicating acounted value is allocated to b3-b0.

A value 2 of b7-b5 indicates that the main data is search data. In thiscase, data indicating whether the search data is video or audio data isallocated to b4 of b4-b0, and data indicating a search speed isallocated to b3-b1. As shown in FIG. 12, by way of example, a value 1 ofb3-b1 indicates a 4-time speed; a value 2 indicates an 8-time speed; avalue 4 indicates a 16-time speed; and a value 5 indicates a 32-timespeed. Additionally, by designing the rotary head (drum) to rotate at aspeed in a following manner, a search can be performed with a widerrange of adaptable speed for each multiple speed (corresponding to thedrum rotational speed). Furthermore, the search video data is a low-bitrate data resulting from omitting high-frequency components of an Ipicture.

Returning to FIG. 11, a value 3 of b7-b5 indicates that the main data isAUX (auxiliary) data. In this case, data indicating the type (AUX mode)of AUX data is allocated to b4-b2 of b4-b0, by way of example, as shownin FIG. 13.

More specifically, a value 1 of b4-b2 indicates that the AUX data isrelated to the PES video data (AUX-V in FIG. 11), and a value 1indicates that the AUX data is related to the PES audio data (AUX-A). Avalue 2 indicates that the AUX data is PSI (Program SpecificationInformation) (PES-PSI1) corresponding to the first half of the datarecorded in a transport stream format, and a value 3 indicates that theAUX data is PSI (PES-PSI2) corresponding to the second half of thoserecorded data. A value 4 indicates that the AUX data is any ofpredetermined data (called system data; System), shown in FIGS. 14 and15, for each of which a keyword number is set. Though described later inmore detail, FIG. 14 represents the system data fixed in data amount andFIG. 15 represents the system data variable in data amount.

Returning to FIG. 11 again, a value 4 of b7-b5 indicates that the maindata corresponds to the first half of the data recorded in the transportstream format. In this case, a jump flag is allocated to b4 and b3, anda time stamp is allocated to b2-b0. A value 5 of b7-b5 indicates thatthe main data corresponds to the second half of the data recorded in thetransport stream format. In this case, a counted value is allocated tob4-b0.

A value 6 of b7-b5 indicates that no data is recorded as the main data,i.e., it represents NULL. NULL is inserted when an average total amountof main data is less than the recording-enable rate. For example, if therate is 20 Mbps when recorded in the transport stream format, NULL isinserted in amount of about 5 Mbps.

The above-described data of the SB header is supplied from thecontroller 13 through the terminal 3.

The main data recorded in the main sector is the video data suppliedfrom the video data compressing unit 1, or the audio data supplied fromthe audio data compressing unit 2, and the AUX data (system data)supplied from the controller 13 through the terminal 3.

A packet structure of the system data (i.e., the AUX data recorded asthe main data in the main sector with a value 3 being set to b7-b5 ofthe SB header and a value 0 (AUX-V), a value 1 (AUX-A) or a value 4(System) being set to b4-b2, as well as in a data section of a subcodesector) will now be described.

When the system data has a fixed length as shown in FIG. 14, itcomprises a header section (keyword of 1 byte) including the keywordnumber, etc., and a data section (with a fixed length (4 bytes)) forstoring the system data corresponding to the keyword number, as shown inFIG. 16A. Also, when the system data has a variable length as shown inFIG. 15, it comprises a header section (keyword of 1 byte), a datalength section (1 byte) indicating the data length, and a data section(with a variable length (n bytes)), as shown in FIG. 17A.

Further, in this embodiment, plural sets of system data may be recordedin the main sector. In such a case, a plurality of head sections areprovided as shown in FIGS. 16B to 16D when the length of the system datais fixed, and they are provided as shown in FIGS. 17B to 17D when thelength of the system data is variable.

Of 1 byte of each header section (8 bits of b7-b0), b7 sets therein dataindicating whether another subsequent header section follows to therelevant one. More specifically, a value 0 is set in b7 of each headersection, following which no header section is arranged, such as a headersection F1 (FIG. 16A), header section F12 (FIG. 16B), header section F23(FIG. 16C) and a header section Fk (FIG. 16D) shown in examples of FIG.16, or a header section X1 (FIG. 17A), header section X12 (FIG. 17B),header section X23 (FIG. 17C) and a header section Xk (FIG. 17D) shownin examples of FIG. 17.

On the other hand, a value 1 is set in b7 of each header section,following which another header section is arranged, such as a headersection F11, header sections F12, F22 and header sections F31, etc.(except for the header section Fk) shown in the examples of FIG. 16, ora header section X11, header sections X21, X22 and header sections X31,etc. (except for the header section Xk) shown in the examples of FIG.17.

Further, data allocated to b6-b0 of b7-b0 of each header section differbetween the header section arranged at the head (such as the headersections F1, F11, F21 and F31 shown in the examples of FIG. 16, or theheader sections X1, X11, X21 and X31 shown in the examples of FIG. 17)and the other header sections arranged in second and subsequentpositions (such as the header sections F12, F22, F23 and F32-Fk shown inthe examples of FIG. 16, or the header sections X12, X22, X23 and X32-Xkshown in the examples of FIG. 17).

Of b6-b0 of each header section arranged at the head, b6 sets thereindata indicating whether the length of the system data is fixed orvariable. More specifically, a value 0 indicating the length of thesystem data being fixed is set in b6 of the header section F1, headersection F11, header section F21 and the header section F31 shown in theexamples of FIG. 16, and a value 1 indicating the length of the systemdata being variable is set in b6 of the header section X1, headersection X11, header section X21 and the header section X31 shown in theexamples of FIG. 17.

In the remaining b5-b0 of each header section arranged at the head, anyof the keyword numbers (0 to 63) shown in FIG. 14, i.e., one keywordnumber of the system data having a fixed length, is set.

On the other hand, in b6-b0 of each of the header sections arranged atthe second and subsequent positions, any of the keyword numbers (64 to127) shown in FIG. 15, i.e., one keyword number of the system datahaving a variable length, is set.

FIG. 18 shows collectively the above-described data allocated in theheader section arranged at the head (FIG. 18A) and the header sectionsarranged at the second and subsequent positions (FIG. 18B).

FIGS. 19 and 20 represent, in the bit-array form, the system data havinga fixed length (FIGS. 14 and 16) and the system data having a variablelength (FIGS. 15 and 17), respectively.

Note that the above-described system data is also recorded as subcodedata in the subcode sector described later.

The parity C1 (FIG. 9) is calculated by the error code and ID addingunit 5 from the ID, SB header and the main data for each sync block, andthen added.

Of 141 sync blocks, 18 sync blocks are used for the sync, ID, parity C2,and the parity C1. The parity C2 is obtained by calculating the SBheader or the main data in the vertical direction in FIG. 9. Thiscalculation is executed in the error code and ID adding unit 5. By soselecting 18 sync blocks, a percentage of the number of sync blocks ofthe parity C2 with respect to the total number (141) of sync blocks isgiven by 12.7% (=18/141). This value is larger than the percentage(12.5% (=2 tracks/16 tracks)) that is required to develop the abilityfor correcting a continuous error over two or more tracks.

FIG. 21 shows average values of the AUX data, video data, audio data,search data, parity C1, and the parity C2 recorded as the main databefore the 24–25 conversion.

More specifically, the average values of the numbers of sync blocksconstituting the AUX data, video data, audio data, and the search dataare respectively 7.5, 113, 1.75 and 7.5. Thus, bit rates of these datain average are given as follows: $\begin{matrix}{{{AUX}\mspace{14mu}{data}} = {95\mspace{11mu}{bytes} \times 0.75\mspace{14mu}{SB} \times 300\mspace{14mu}{tracks}\; \times 8\mspace{14mu}{bits}}} \\{= {171\mspace{14mu}{kbps}}}\end{matrix}$ $\begin{matrix}{{{video}\mspace{14mu}{data}} = {95\mspace{14mu}{bytes} \times 113\mspace{14mu}{SB} \times 300\mspace{14mu}{tracks} \times 8\mspace{14mu}{bits}}} \\{= {25.764\mspace{14mu}{Mbps}}}\end{matrix}$ $\begin{matrix}{{{audio}\mspace{14mu}{data}} = {95\mspace{11mu}{bytes} \times 1.75\mspace{14mu}{SB} \times 300\mspace{14mu}{tracks}\; \times 8\mspace{14mu}{bits}}} \\{= {339\mspace{14mu}{kbps}}}\end{matrix}$ $\begin{matrix}{{{search}\mspace{14mu}{data}} = {95\mspace{11mu}{bytes} \times 7.5\mspace{14mu}{SB} \times 300\mspace{14mu}{tracks}\; \times 8\mspace{14mu}{bits}}} \\{= {1710\mspace{14mu}{kbps}}}\end{matrix}$Eventually, a total bit rate is given by 28.044 (=171 kbps+25.764Mbps+339 kbps+1710 kbps) Mbps, and this rate is sufficient to record theHD video data, audio compressed data, AUX data, and the search videodata by MP@HL or MP@H-14. Note that 95 bytes mean the data amount of theSB header and the main data in one sync block.

Subsequent to the main sector, a subcode sector (FIG. 7) of 1250 bits isarranged. FIG. 22 shows a structure of the subcode sector.

The subcode sector in one track has a length of 1250 bits (in terms of avalue after the 24–25 conversion) and comprises 10 subcode sync blocks.

One subcode sync block is made up of a sync of 16 bits, ID of 24 bits,subcode data of 40 bits, and a parity of 40 bits. Thus, the length ofone subcode sync block is 120 bits (in terms of a value before the 24–25conversion), which is about 1/7 of the length (888 bits) of one syncblock of the main sector described above. By setting the data length ofthe subcode sync block to be so short, the contents of the subcode syncblocks can be surely read even with high-speed playback on the order of200-time speed, and therefore a high-speed search can be performed.

The sync in the subcode sector differs from the sync added to the mainsector so that the main sector and the subcode sector may bedistinguished based on such a difference in the sync. The sync in thesubcode sector is added by the sync generator 7 in FIG. 2.

The sync block ID is made up of, as shown in FIG. 23A, three IDs, i.e.,ID0 to ID2, each having a length of 1 byte.

As with ID0 in the main sector of FIG. 10A, ID0 defines the format typeand the track pair number.

Of b7-b0 of ID1, b3-b0 define the subcode sync block number, and b7-b4are reserved bits.

The sync block number is one of numbers 0–9 that are assignedrespectively to 10 subcode sync blocks contained in the subcode sectorof one track.

As with ID2 in the main sector, one byte of overwrite protect isallocated to ID2. In the subcode sector, if ID2 indicates that therecorded data is underlying one, the processing is executed after makingall of the sync blocks invalid (i.e., on a judgment that all of the syncblocks have not been acquired).

FIG. 23B shows ID0–ID2 contained in the 10 subcode sync blocks. TheseID0–ID2 are added by the error code and ID adding unit 5.

The subcode data arranged subsequent to the subcode sync block ID is thesystem data having a fixed length shown in FIG. 14. In other words, thesubcode data is recorded in the form as shown in FIGS. 16 and 19.Further, the type of subcode data differs between a user tape and theso-called Pre-REC tape. In the case of a user tape, as shown in FIG.24A, the tape position information (ATNF), title time code (TTC),recording date, and the recording time are recorded as the subcode data.In the case of a Pre-REC tape, as shown in FIG. 24B, the tape positioninformation (ATNF), title time code (TTC), part number, and the chapterstart position are recorded as the subcode data. Stated otherwise, in aPre-REC tape, the part number and the chapter start position areincluded in the subcode data respectively in place of the recording dateand the recording time in a user tape.

The subcode data is supplied from the controller 13 through the terminal3 shown in FIG. 2.

FIG. 25 shows a data structure of the subcode sync ID and the subcodedata in the conventional DV format. As seen from FIG. 25, theconventional DV format is not able to record the data positioninformation (EPO in ATNF), etc. that are recorded in the presentinvention.

Returning to FIG. 22, the parity of 40 bits is arranged subsequent tothe subcode data. This parity is added by the error code and ID addingunit 5.

Subsequent to the subcode sector, the postamble (FIG. 7) is arranged. Aswith the preamble, the postamble is also recorded in combination of thepattern A and the pattern B shown in FIG. 8. The postamble has a lengthof 1500 bits when the head rotation is synchronized with 60×1000/1001Hz, and has a length of 1375 bits when it is synchronized with 60 Hz.

The system data shown in FIGS. 14 and 15 will be described below in moredetail.

As described above, FIG. 14 shows the system data having a fixed lengthalong with the keyword number. For example, tape position information(ATNF) corresponding to the keyword number 4 represents system datahaving a fixed length, which is made up of an absolute position(ATN=Absolute Track Number) of 23 bits, a break flag (B flag) of 1 bit,and edit information of 8 bits.

The absolute position (ATN) indicates the distance (absolute position)of the track from the tape head.

The B flag is a flag set to “0” when the absolute position (e.g.,number) is continued, and set to “1” when the absolute position is notcontinued. By so setting the B flag, it is possible to assign themonotonously increasing numbers even in the case where data is recordedin mixed fashion and the absolute position is not continued. Thus, asearch can be accurately performed because of no return in the assignednumber.

The edit information comprises, as shown in FIG. 26, 8 bits of b7-b0. AnI flag is allocated to b7. The I flag is set to “1” when informationindicating a location to make a search (i.e., information indicating alocation that is designated at the time of recording) is contained inthe main sector corresponding to the subcode sector. A search positionis detected based on the I flag.

A P flag is allocated to b5. The P flag is set to “1” when recordingstart video data for a still picture is contained in the main sectorcorresponding to the subcode sector. A position at which a still pictureis recorded is detected based on the P flag.

An EH flag is allocated to b4. The EH flag is set to “1” when an I or Ppicture is recorded in the main sector corresponding to the subcodesector. Usually, editing, such as splicing between scenes on the tape,is started from an I or P picture. An edit position can be thereforedetected based on the EH flag.

An edit picture header offset (EPO) is allocated to the remaining b3-b0.The EPO indicates the position of the main sector, to which the subcodesector corresponds, in units of 16 tracks. The EPO will be described inmore detail with reference to FIG. 27. In an example of FIG. 27, thevalue of EPO is 5 for a subcode sector in which the TTC has a value 0,and this subcode sector is arranged in a predetermined track in whichthe ECC number (number assigned in units of 16 tracks) is 6. It istherefore understood that the main sector, to which the above subcodesector corresponds, is arranged in a track preceding the relevant track,in which the subcode sector is arranged, by the EPO value 5×16 tracks.Accordingly, it is possible to detect in which main sector an I or Ppicture serving as an edit point is actually recorded.

The above-mentioned system data is recorded in the main sector and thesubcode sector as described above.

The AUX data having a variable length, shown in FIG. 15, will bedescribed below. The AUX data is recorded only in the main sector.

For example, ECCTB (track block) corresponding to the keyword number 80represents a packet including plural items of AUX data denoted by marksO in FIG. 28, including the length-fixed AUX data (such as the dataposition information (ATNF) and TTC) shown in FIG. 14. The packetincludes, by way of example, as 3-byte audio mode, an audio frame size(3 bits), sample frequency (3 bits), etc., as shown in FIG. 29. Also,the packet includes, as video mode, a video rate (24 bits), etc., asshown in FIG. 30. Further, the packet includes, as DATA-H, informationindicating the type of picture, etc., as shown in FIG. 31.

The operation of the apparatus shown in FIG. 2 will be described below.An HD video signal is inputted to the video data compressing unit 1together with search video data (thumbnail video data), in which it iscompressed by MP@HL or MP@H-14, for example. An audio signal is inputtedto the audio data compressing unit 2 and compressed therein. Subcodedata, AUX data, a header, etc. are supplied to the terminal 3 from thecontroller 13.

The switch 4 is controlled by the controller 13 to take in video data(including search video data) outputted from the video data compressingunit 1, audio data outputted from the audio data compressing unit 2, andsystem data inputted through the terminal 3 at the predetermined timing,and then deliver those data to the error code and ID adding unit 5 formerging thereof.

The error code and ID adding unit 5 adds an ID of 24 bits to each ofsync blocks of the main sector shown in FIG. 9. Also, the error code andID adding unit 5 calculates and adds a parity C1, shown in FIG. 9, foreach sync block. Further, for 18 ones of 141 sync blocks, the error codeand ID adding unit 5 adds a parity C2 in place of an SB header and maindata.

Furthermore, the error code and ID adding unit 5 calculates and adds anID of 24 bits and a parity of 40 bits for each subcode sync block of thesubcode data, as shown in FIG. 22.

In addition, the error code and ID adding unit 5 holds data in amountcorresponding to 16 tracks in the main sector and interleaves those dataamong the 16 tracks.

The 24–25 converter 6 converts the data supplied from the error code andID adding unit 5 in units of 24 bits into data in units of 25. As aresult of this 24–25 conversion, components of the tracking pilotsignals having frequencies f1 and f2, shown in FIGS. 4 to 6, appear atenhanced levels.

The sync generator 7 adds a sync of 16 bits to each of the sync blocksof the main sector, as shown in FIG. 9. Also, the sync generator 7 addsa sync of 16 bits to each of the subcode sync blocks of the subcodesector, as shown in FIG. 22. Further, the sync generator 7 generates therun patterns, shown in FIG. 8, for a preamble and a postamble.

More particularly, addition (merging) of those data is carried out bythe controller 13 changing over the switch 8 so that the data outputtedfrom the sync generator 7 and the data outputted from the 24–25converter 6 are selected at the appropriate timing for supply to themodulator 9.

The modulator 9 modulates the inputted data by a method adaptable forthe DV format, and outputs modulated data to the parallel/serialconverter 10. The parallel/serial converter 10 converts the inputtedparallel data into serial data, and supplies the serial data to therotary head 12 through the amplifier 11. The rotary head 12 records theinputted data on the magnetic tape 21.

FIG. 32 represents data, which has a GOP (Group of Picture) structurewith N=15 (an I picture is arranged for each 15 pictures) and M=3 (a Ppicture is arranged for each 3 pictures), in a state where the data isrecorded on the magnetic tape 21 after being processed as describedabove. More specifically, pictures in number indicated by a value of Mare set as one unit, and AUX data (denoted by U in FIG. 32) related tothose pictures, audio data (denoted by A in FIG. 32) corresponding tothose pictures, and AUX data (denoted by X in FIG. 32) related to theaudio data are arranged together at the head of 16 tracks that undergointerleaving. Subsequent to those data, one unit of pictures (3 picturesin the illustrated example) is arranged.

In other words, since AUX data having a variable length is prepared andrecorded in the main sector, it is possible to record such AUX datatogether for each unit comprising a predetermined number of pictures. Asa result, the AUX data can be recorded with high efficiency.

Also, since the subcode sector records therein an EPO indicating thedistance up to the main sector corresponding to the AUX data (datahaving a fixed length) recorded in that subcode sector, thecorresponding main sector can be easily detected.

FIG. 33 shows, by way of example, the case where the corresponding mainsector is detected by correcting an object value of the TTC based on theEPO and then utilizing a corrected value.

The EPO can be determined by the following formula:EPO=recording track number of subcode_(—) TTC at edit point/16−recordingtrack number of main PIC _(—) TTC corresponding to subcode_(—) TTC/16

In the above formula, 1/16 is multiplied for conversion into the ECCblock number. Also, since subcode_(—)TTC records the same datarepeatedly for each 10 tracks, an offset value is obtained in averageframe units.

Accordingly, a target position can be detected in advance during searchtravel (at the time when reaching the object TTC). In this case,however, history information for the offset is required (that is to say,the ECCTB must be prepared to shorten a pre-playback time).

Since the ECCTB (denoted by H in the drawings) is arranged at the headof 16 tracks that undergo interleaving, a time of pre-playback performedfor, e.g., splicing between scenes on the tape can be shortened. Statedotherwise, the AUX data required for pre-playback is inherently recordedin the subcode, but as described above, the subcode sector is arrangedwith a time lag relative to the corresponding main sector. Referring tosuch AUX data therefore prolongs a pre-playback time correspondingly.

FIG. 34 shows collectively the AUX data (U) related to the pictures, theAUX data (X) related to the audio data, the ECCTB, and the datacontained in the subcode.

FIG. 35 shows another example of generating the EPO in a differentmanner. In this example, the EPO can be determined by the followingformula:EPO=track head in ECC (=subcode_(—) TTC−main PIC _(—) TTC)

Accordingly, recording for slicing between scenes on the tape can beperformed without history information of the EPO. In this case, however,it is required in search travel to approach the TTC (target position),which has been resulted from the offset correction, after reaching theTTC before the offset correction.

In the example of FIG. 35, the subcode sector in which the TTC has avalue 0 is arranged in a track T0 of EEC6 (the EEC number being 6).Stated otherwise, the corresponding main sector, which is arranged in atrack T0 of ECC0, can be detected by going back from the track T0 ofEEC6 by 9×16 tracks. Additionally, since the subcode sector arranged ineach track of ECC6 corresponds to the main sector where an I picture isrecorded, the EH header for the subcode sector is set to “1”.

FIG. 36 shows one example of construction of a playback system forreproducing the data recorded on the magnetic tape 21 as describedabove.

The rotary head 12 reproduces the data recorded on the magnetic tape 21and outputs the reproduced data to an amplifier 41. The amplifier 41amplifies and supplies the inputted signal to an A/D converter 42. TheA/D converter 42 converts the inputted analog signal into a digitalsignal and supplies it to a demodulator 43. The demodulator 43demodulates the data supplied from the A/D converter 42 by a methodcorresponding to the modulation method used in the modulator 9 of FIG.2.

From the data demodulated by the demodulator 43, a sync detector 44detects the sync for each sync block of the main sector shown in FIG. 9and the sync for each subcode sync block of the subcode sector shown inFIG. 22 for supply to an error correcting and ID detecting unit 46. A25-24 converter 45 converts the data supplied from the demodulator 43 inunits of 25 bits into data in units of 24 bits corresponding to theconversion made in the 24–25 converter 6 of FIG. 2, and outputsconverted data to the error correcting and ID detecting unit 46.

The error correcting and ID detecting unit 46 executes an errorcorrecting process, an ID detecting process, and an interleaving processbased on the syncs inputted from the sync detector 44.

A switch 47 is controlled by the controller 13 and outputs, of dataoutputted from the error correcting and ID detecting unit 46, video data(including search video data) to a video data decompressing unit 48,audio data to an audio data decompressing unit 49, and system data, suchas subcode data and AUX data, to the controller 13 through a terminal50.

The video data decompressing unit 48 decompresses the inputted videodata and outputs it as an analog HD video signal after D/A conversion.The audio data decompressing unit 49 decompresses the inputted audiodata and outputs it as an analog audio signal after D/A conversion.

The operation of the playback system thus constructed will be describedbelow. The rotary head 12 reproduces the data recorded on the magnetictape 21 in the form shown in FIG. 32. The reproduced data is amplifiedby the amplifier 41 and then supplied to the A/D converter 42. Digitaldata converted from the analog data by the A/D converter 42 is inputtedto and demodulated by the demodulator 43.

The 25-24 converter 45 converts the demodulated data from thedemodulator 43 in units of 25 bits into data in units of 24, and outputsthe converted data to the error correcting and ID detecting unit 46.

From the data outputted from the demodulator 43, the sync detector 44detects each sync of the main sector shown in FIG. 9 and each sync ofthe subcode sector shown in FIG. 22 for supply to the error correctingand ID detecting unit 46. The error correcting and ID detecting unit 46stores data in amount corresponding to 16 tracks and executes theinterleaving process, and also executes the error correcting processusing each parity C1, C2 of the main sector shown in FIG. 9. Further,the error correcting and ID detecting unit 46 detects each SB header ofthe main sector, and determines which one of audio data, video data, AUXdata, search video data, etc. is contained in each sync block.

In addition, the error correcting and ID detecting unit 46 executes theerror correcting process of the subcode data using each parity of thesubcode sector shown in FIG. 22, and detects a packet keyword (header)of the AUX data to determine the contents of the subcode data. It ishence determined whether the subcode data represents the track number orthe time code number.

Based on the SB header detected by the error correcting and ID detectingunit 46, the switch 47 supplies both the video data and the search videodata to the video data decompressing unit 48. The video datadecompressing unit 48 decompresses the inputted data by a methodcorresponding to the compression method used in the video datacompressing unit 1 of FIG. 2, and then outputs the decompressed data asa video signal.

Also, the switch 47 outputs the audio data to the audio datadecompressing unit 49. The audio data decompressing unit 49 decompressesthe inputted audio data by a method corresponding to the compressionmethod used in the audio data compressing unit 2 of FIG. 2, and thenoutputs the decompressed data as an audio signal.

Further, the switch 47 outputs the AUX data, the subcode data, etc.delivered from the error correcting and ID detecting unit 46 to thecontroller 13 through the terminal 50.

Thus, the data, including pictures and audio data, recorded in the formshown in FIG. 32 is decompressed.

While the above description has been made, by way of example, inconnection with the case of decompressing pictures and audio datarecorded on the magnetic tape 21, the decompressed data may bemultiplexed to produce MPEG data.

A sequence of the above-described processing can be executed withhardware, but it may also be executed with software. When executing asequence of the above-described processing with software, a programconstituting the software is installed from a storage medium to, e.g., acomputer incorporated in dedicated hardware, or a universal personalcomputer capable of executing various functions when various programsare installed therein.

As shown in FIGS. 2 and 36, such a storage medium may be in the form ofpackage media, such as a magnetic disk 31 (including a floppy disk), anoptical disk 32 (including CDROM (Compact Disk—Read Only Memory) and DVD(Digital Versatile Disk)), a magneto-optical disk 33 (including MD(Mini-Disk)), and a semiconductor memory 34, which store the programtherein and are distributed separately from a body of the magnetic taperecording/playback apparatus to provide the program to a user. Inaddition, the storage medium may be a ROM, a hard disk or the like,which stores the program therein and is provided to a user in a stateassembled in the apparatus body beforehand.

It is to be noted that the steps describing the program stored in astorage medium can be processed in time series following the sequencedescribed in the specification, but may also be processed in parallel orindividually without being always restricted to the time-serialprocessing.

With the magnetic tape recording apparatus, the magnetic tape recordingmethod, and the storage medium product storing the computer-readableprogram according to the present invention, as described above, one ofvideo data, audio data or search data and auxiliary data having avariable length and related to any of those data is acquired as firstgroup data, and data containing a subcode related to the first groupdata is acquired as second group data. The first group data and thesecond group data are merged such that the first and second group dataare continuously arranged on tracks of a magnetic tape without beingspaced away from each other. Merged data is supplied for recording onthe magnetic tape. Therefore, data having a large amount of information,represented by data of an HD video signal, can be recorded on themagnetic tape in a digital manner.

With the format for a magnetic tape according to the present invention,since the first group data and the second group data are merged suchthat the first and second group data are continuously arranged on tracksof the magnetic tape without being spaced away from each other, amagnetic tape can be realized which records data requiring a largecapacity as represented by data of an HD video signal.

With the magnetic tape playback apparatus, the magnetic tape playbackmethod, and the storage medium product storing the computer-readableprogram according to the present invention, the auxiliary data isacquired, as first group data, from data reproduced from a magnetic tapewith a rotary head, and the data reproduced from the magnetic tape isprocessed based on the acquired auxiliary data. The HD video data can betherefore played back with certainty.

1. A magnetic tape recording apparatus for recording digital data on amagnetic tape with a rotary head, said apparatus comprising: firstacquiring means for acquiring video data, audio data or search data;second acquiring means for acquiring auxiliary data having a variablelength and related to the data acquired by said first acquiring means;selecting means for selecting, as first group data, one of the dataacquired by said first acquiring means and the data acquired by saidsecond acquiring means; third acquiring means for acquiring second groupdata containing a subcode related to said first group data; mergingmeans for merging said first group data and said second group data suchthat said first group data and said second group data are continuouslyarranged on tracks of said magnetic tape without being spaced away fromeach other; and supplying means for supplying data merged by saidmerging means to said rotary head to record the merged data on saidmagnetic tape.
 2. A magnetic tape recording apparatus according to claim1, wherein said first acquiring means acquires, as said first groupdata, the video data in edit units.
 3. A magnetic tape recordingapparatus according to claim 1, wherein said second acquiring meansacquires, as said second group data, auxiliary data related to the audiodata and auxiliary data related to the video data; and said mergingmeans merges the auxiliary data related to the audio data, the audiodata, the auxiliary data related to the video data, and the video datato be arranged in this order.
 4. A magnetic tape recording apparatusaccording to claim 1, wherein said second acquiring means furtheracquires auxiliary data required for pre-playback; and said mergingmeans merges the auxiliary data required for pre-playback to be arrangedat the head of an edit unit of the video data.
 5. A magnetic taperecording apparatus according to claim 4, wherein the auxiliary datarequired for pre-playback includes the contents recorded in a subcodesector.
 6. A magnetic tape recording method used in a magnetic taperecording apparatus for recording digital data on a magnetic tape with arotary head, said method comprising the steps of: a first acquiring stepof acquiring video data, audio data or search data; a second acquiringstep of acquiring auxiliary data having a variable length and related tothe data acquired by processing in said first acquiring step; aselecting step of selecting, as first group data, one of the dataacquired by processing in said first acquiring step and the dataacquired by processing in said second acquiring step; a third acquiringstep of acquiring second group data containing a subcode related to saidfirst group data; a merging step of merging said first group data andsaid second group data such that said first group data and said secondgroup data are continuously arranged on tracks of said magnetic tapewithout being spaced away from each other; and a supplying step ofsupplying data merged by processing in said merging step to said rotaryhead to record the merged data on said magnetic tape.
 7. A storagemedium product storing a computer-readable program executed by acomputer to perform a method comprising the steps of: a first acquiringstep of acquiring video data, audio data or search data; a secondacquiring step of acquiring auxiliary data having a variable length andrelated to the data acquired by processing in said first acquiring step;a selecting step of selecting, as first group data, one of the dataacquired by processing in said first acquiring step and the dataacquired by processing in said second acquiring step; a third acquiringstep of acquiring second group data containing a subcode related to saidfirst group data; a merging step of merging said first group data andsaid second group data such that said first group data and said secondgroup data are continuously arranged on tracks of a magnetic tapewithout being spaced away from each other; and a supplying step ofsupplying data merged by processing in said merging step to a rotaryhead to record the merged data on said magnetic tape.